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Thanks to Professor David Cohen, Herzliya Medical Center (Israel), for contributing this case.
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CancerTYPE ID is a standardized, objective molecular test based on the differential expression of 92 genes, that classifies tumors by matching the gene expression pattern of a patientís tumor tissue to a database of known tumor types and histological subtypes.

CancerTYPE IDís database includes 2,206 tumors from multiple tumor banks, selected to provide broader and deeper representation of the heterogeneity of tumors. The 92-gene assay does not overlap with IHC markers, providing complementary data to standard tumor diagnosis.

(1) As we begin our 11th year, we thank you for your support. This year, we plan to increase the frequency of chapter updates, add more images and videos, and start adding smartphone / iPad apps. Let us know if you have any other comments or suggestions.

(2) We are looking for reviewers for part/all of these chapters: Coagulation, Salivary Glands, Stains, Uterus; also Fallopian Tubes, Lung-tumor, Ureters, Urethra, Vagina, Vulva. If interested, contact Liz at [email protected], and send a copy to [email protected].

(3) We have updated the Skin-nontumor chapter based on reviews by Ha Kirsten Do, M.D., IUPUI; Mowafak Hamodat, MB.CH.B, MSc., FRCPC, Eastern Health, St. Johns (Canada); Nat Pernick, M.D., PathologyOutlines.com, Inc. and Cecilia Rosales, M.D., Baylor College. Over the next several months, we will be adding more images and references to these topics.

Case of the Week #213

Clinical History:

A 48 year old man had prolonged diarrhea, with a clinical impression of inflammatory bowel disease or microscopic colitis. A colonic biopsy was obtained.

Micro images:

Row 1: H&E
Row 2: PAS

What is your diagnosis?

Diagnosis:

Intestinal Spirochetosis

Discussion:

Sections show colonic mucosal biopsies with a lamina propria that is mildly expanded by inflammatory cells including eosinophils and mononuclear inflammatory cells. The mucosal glands appear normal under low power, but on high power the luminal surface shows a "blue fringe," which is strongly positive with PAS where filamentous organisms are present.

As in this case, histology shows an accentuation of the luminal border by spirochetes, which produce a blue line on H&E between the microvilli of the covering epithelium (Pathologe 2003;24:192). The spirochetes are accentuated by silver stains (Warthin-Starry, Dieterle), as well as PAS, Giemsa and Alcian-blue (pH 2.5). There is usually minimal inflammation present.

Electron microscopy shows long coiled bacteria adherent to the microvilli: